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| -rw-r--r-- | guides/source/active_record_querying.md | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md index 673dcfc1d3..486e7b80ff 100644 --- a/guides/source/active_record_querying.md +++ b/guides/source/active_record_querying.md @@ -1160,10 +1160,11 @@ Even though Active Record lets you specify conditions on the eager loaded associ However if you must do this, you may use `where` as you would normally. ```ruby -Article.includes(:comments).where("comments.visible" => true) +Article.includes(:comments).where(comments: { visible: true }) ``` -This would generate a query which contains a `LEFT OUTER JOIN` whereas the `joins` method would generate one using the `INNER JOIN` function instead. +This would generate a query which contains a `LEFT OUTER JOIN` whereas the +`joins` method would generate one using the `INNER JOIN` function instead. ```ruby SELECT "articles"."id" AS t0_r0, ... "comments"."updated_at" AS t1_r5 FROM "articles" LEFT OUTER JOIN "comments" ON "comments"."article_id" = "articles"."id" WHERE (comments.visible = 1) @@ -1171,7 +1172,19 @@ This would generate a query which contains a `LEFT OUTER JOIN` whereas the `join If there was no `where` condition, this would generate the normal set of two queries. -If, in the case of this `includes` query, there were no comments for any articles, all the articles would still be loaded. By using `joins` (an INNER JOIN), the join conditions **must** match, otherwise no records will be returned. +NOTE: Using `where` like this will only work when you pass it a Hash. For +SQL-fragments you need use `references` to force joined tables: + +```ruby +Article.includes(:comments).where("comments.visible = true").references(:comments) +``` + +If, in the case of this `includes` query, there were no comments for any +articles, all the articles would still be loaded. By using `joins` (an INNER +JOIN), the join conditions **must** match, otherwise no records will be +returned. + + Scopes ------ |